Tennis ball cover



Deco 1Q, 1935. [3 w 2,023,673

TENNI 5 BALL COVER Filed March 22, 1954 INVENTOR [Ma/4r W. ELL/5ATTORNEYS necessary to render the composite fabric as a heavily feltedwoolen fabric having both sides with a thick napped surface. 7

The hard spun yarn 5 in the felted fabric retains its form with muchless spreading of fiber over the felted portion than the soft spun yarn4.

And this is desirable because the yarn 5 with its hard twist is designednot only to give a' roughened surface to the ball (except as the surfaceis smoothed up by a heavy nap) but also to make such roughened surface along wearing surface V;

which hard spun yarn will do. The arrangement is also desirable withrespect to yarn 4, because the body fabric of this yarn is on the'sidecemented to the ball. What there is left of the tightly woven bodyfabric (after fulling and spreading its fibers to make the feltedcomponent) is held down against the ball by the ocment which, inaddition to the tight weave, givessheets with my preferred arrangementof yarns and felted fibers all positioned to work together in resistingthe wear on the ball.

The composite fabricpreferably made as described is formed and attachedto the ball to give it the improved cover construction. The body sheetof yarn 4 is on the bottom next to the ball, see Fig. 6 inwhich therubber ball component is R and the cement S. The wearing sheet of yarn 5is on top of the body sheet and anchored into the body by the tie-ins I(see Fig. 8) of the composite weave, by the felted fiber F (Fig.8)fillingall the interstices of the composite weave, and by the factthat all these components have been through a big shrinkage operation tolock them in their relative positions (as indicated generally by thedetail of .the surface shown in Fig. 1; the same surface, of course,extends all over the ball). 7

After this has been done and the tennis ball is ready for play, I havefound by actual practice that the wear on the ball normally proceeds asfollows: The original nap is worn off. The peaks of. the crosses C areuncovered and provide wearing pimples all over the face of the ball.These pimples are gradually worn down and while they are wearing downnap is gradually supplied for the surface of the ball from theconcavities or valleys between the pimples, as can be readilyappreciated from enlarged view Fig. 8. The top bar of each cross wearsout. This makes broken ends of yarn 5. Such ends are opposite ends ofthe small lengths of yarn 5 originally divided to make the top bar ofthe crosses. These short lengths are tied tightly at 1 into the bodyfabric. When broken through at the centers (which are highand take thewear first) such short lengths are up-ended and present little tuftsover the surface of the ball. Such tufts are still anchored into thebody fabric and the broken ends are not long enough (see proportions ofFig. 1) to give an unraveled or loose end appearance to the'ballsurface. The tufts are distributed with enough frequency all over thesurface of the ball thatthey do not give a w ornout appearance to theball. On the contrary the surface of the ball is given a good napcondition and appearance, with assurance of continued life in the ball.The under bars of the crosses are worn through and their tufts arepresented with the same result of continued good nap condition andappearance. While this is going on the felted fibers in the valleysbetween ridges of yarn 5 yield additional nap. Finally all the yarn 5 isworn off the ball. The only thing left to wear is the body fabric in thesheet of yarn 4. I have discovered a surprising wearing quality in thissheet of yarn 4 after the yarn 5 has been entirely worn off its topface. And this feature of my invention needs a little specialconsideration.

If the tennis ball cover were made of easily felted yarn 4 tightly wovenand without the sheet of yarn 5, it would be an ordinary tennis ballcover of the prior art. Such covers have been used for many years. 4With such a prior art cover the life of the tennis ball under hard playis very short. The difficulty has been that when the nap wears down tothe tightly woven yarn, the latter is worn smooth and there is then nonap on the ball. This takes place either in spots or all over the ball.In either case there is the tendency for the ball to float when itssurface is too smooth to grip theair for proper travel and spin.Considered academically, one would suppose that the same kind of tightlywoven body fabric would act the same way when a superimposed sheet ofwearing fabric was worn ofi the body fabric. But I have discovered inthe experiments leading to and the actual practice of my invention thatthe body fabric of yarn 4, when that is all that is left on the ball(after my other components have worn off), will act quite differentlythan if such body fabric were the original and sole component of thecover. Fig. 2 indicates the difference. There is a sufficientlyroughened surface on the worn ball for continued play when only the bodyfabric is left. This results from the great number of uniformlydistributed small recesses or pits 8 all overthe ball. They are notlarge but they are larger than the interstices of the body fabric andlarge enough to prevent the smoothness that has been objectionable.

This roughness in the tightly woven body fabric comes, I believe, fromthe fact that such fabric is a component part of a composite fabric thathas had a sheet of wearing fabric (like yarn 5 presents) combined withit and worn off its surface. After that has been done the body fabrictakes a different top surface than if it had been used alone for thetennis ball cover, as it has been in the past. Specifically, I believethat such roughened surface is caused by the slight displacement ofthreads in even a very tightly woven fabric due to the presence of thesecond sheet of threads making up the composite weave. This slightdisplacement for example of yarns 4 in its tight body fabric weave takesplace in line with and due to the presence of yarn 5 tied in on the topsurface of the body fabric. As the yarn 5 is higher than the bodyfabric, and as it Wears away, it is pressed into the body fabric toaccentuate any possible depressions in the top surface of the bodyfabric. And when yarn 5 is worn off the top surface of the cover thenhas the pits or depressions 8 I have pointed out. Whatever the cause is,the body fabric is in fact rendered with a suitable playing surface dueto its slight roughness. And it cannot be worn smooth until it is wornsufficiently in depth to obliterate the pits or depressions in it. Ihave found that these are sufficiently deep to materially prolong thelife of the tennis ball.

If the Weave of yarn were used as a single sheet, it would not serve mypurpose. If the skeleton for a felt-ed cover surface is merely roughenedby disposing of its felted fabric in a single sheet, it soon wears out.The skeleton fabric yarn arrangement in any open or fancy fabric ofsingle sheet character is necessarily weak and sleazy. This is true ofmy particular arrangement of yarn 5 as a single sheet form without thesheet of yarn 5. And it is true of other arrangements of yarn 5 whichcould be referred to as fancy weaves or fabrics in single sheet form.

As I have intended to point out, my invention is not to be found in asingle sheet form of fabric but in a two-sheet fabric of composite formin which each ply or sheet combines to make the other one functiondifferently in the tennis ball use than either one can function alone.It is true, however, that of I desired to have a tennis ball with asingle layer of closely woven felted fabric and of improved form, Icould arrive at that result by making the tennis ball with my compositecover, putting it in a machine to take off the top sheet (of yarn 5) bymachine wear and leave only the body fabric sheet on the ball. The ballto be sold would then have a cover of improved form derived from thecomposite sheet, as indicated in Figs. 2 and 7. And it would embody adistinct feature of my invention which is novel and useful in the cover.But my invention is primarily found in the characteristics of a tennisball made with the composite sheets combined for prolonged wear whilemaintaining the playing quality of the ball.

By consolidating the two sheets of yarn, locked together by thecomposite weave and by the heavy felting and big shrinkage due tofulling of the yarns in their composite form and constructing the rubberball portion with this form for covering, 'I make a tennis ball thatwill outwear any prior art tennis ball of which I am aware. And exceptfor its superior wearing qualities and continued good appearance the newball will have the standard qualities of the best tennis balls. Thethickness and weight per unit area of cover can be substantially thesame in the new ball as under prior art standards, which is a help inmanufacture and in the introduction of the ball on the market.

In the drawing it is not possible to show the exact relative arrangementof all the yarn and felted fiber making up the improved cover. The yarnsbecome so heavily covered with felted fiber that they are submerged inthe mass. The showing is necessarily skeletonized to a considerabledegree. The general nature of a heavily felted woolen cloth is, however,well understood and it should be understood that in this respect mydrawing necessarily omits much of the felting fiber that would hide theyarn arrangement shown. With this explanation one skilled in the artwill fuliy understand the nature of the invention and be able to put itin practice with such variations as come within the scope of itsconstruction principles.

Having disclosed my invention, what I claim is:

l. A tennis ball constructed with a woolen cover, said cover consistingof two sheets of yarn woven together one on top of the other each sheethaving warp and weft threads, the inner sheet being closely woven andthe outer sheet being loosely Woven with its threads spaced apart aplurality of times as far as the threads of the inner sheet and thewhole felted and tied together in tightly locked composite form, saidtwo sheets of yarn being tied together in the weaving at points spacedclosely enough together to prevent loose ends of any substantial lengthas the sheet on the outer side of the ball wears through.

2. A tennis ball constructed with a center por- 5 tion of rubber and awoolen cover portion, the latter comprising a composite weave of aheavily felted and tightly woven body fabric and an open woven wearingfabric on top of and tightly tied in at spaced points to the bodyfabric, said wearing fabric being arranged with its threads spaced aparta plurality of times as far as the threads of the inner sheet andsubmerged in felted fiber of the woolen cover and forming a supportingand wearing skeleton for retarding the wearing away of the said feltedfiber.

3. A tennis ball comprising an inflated center portion and a cloth coverportion to take the wear and control the flight, said cover portionconstructed of a tightly woven body fabric made of heavily felted yarnand a wearing fabric made of larger and harder twisted yarn looselywoven in open mesh form, said wearing fabric being tightly tied into thebody fabric at spaced points located midway between the crossing pointsof the heavier yarn weave, the cloth cover being heavily felted with thelarger yarn submerged in the cloth by the felted fibers.

4. In a tennis ball of the type having an inflated rubber center with acover made of felted plain square woven cloth, the combination in thecover portion of two sheets of woven yarn, one sheet made of soft spunsingle yarns tightly woven together and very heavily felted, the othersheet made of heavier hard twisted two-ply yarns loosely woven and lyingon top of the first sheet to roughen the cover, said second sheet havingits yarns tied down tightly into the first sheet at points midwaybetween the crossing points of the heavier yarn, one with another, so asto leave heavy yarn bulges at said crossing points, said two sheetsbeing submerged in felted fiber of the composite'form of cover.

5. In a tennis ball of the type having an inflated rubber ball portion,the combination with'45 the ball portion of a cover portion including atightly woven woolen cloth with a smooth back portion cemented to theball, a loosely woven woolen cloth lying on the face of the other clothto roughen the ball surface for frictional engagement with the air, saidloosely woven cloth being consolidated with the tightly woven cloth byweaving tie-ins at spaced points located between the crossing points ofthe loosely woven cloth, both cloths being shrunk together and submergedin heavily felted fibers filling up the mesh of the loosely woven clothand acting with said tie-ins to consolidate the components of the coverfor interaction during the wearing action of tennis play upon the ball.6O

6. A tennis ball cover construction comprising a tightly woven clothwith a smooth back side for cementing to the ball, a large number ofyarn crosses uniformly distributed over the top side of the woven cloth,the points of the crosses being tied down into the tightly woven clothso as to make the crosses generally convex in form with their highpoints at their centers, a body of felted fiber submerging said crossesand further tying the crosses and woven cloth together by mutual 7 Ofelting of the fibers, the crosses being sufficient in number to give along wearing pimply surface to the ball as it wears in play so as tomaintain frictional resistance for racket and air.

DWIGHT W. ELLIS.

